1. Field of the Invention
The present invention relates to a method and apparatus for handover in a communication system. More particularly, the present invention relates to a method and apparatus for Fast Base Station Switching (FBSS) handover in a communication system.
2. Description of the Related Art
In a communication system, a terminal is provided signal and traffic resources by a serving Base Station (BS). When the terminal moves out of range of the serving BS and into range of a target BS, a hard handover is used to release the signal and traffic resources from the serving BS and allocate the resources of the target BS. However, this hard handover process causes a considerable time delay. If the hard handover occurs during the provision of a service supporting real-time Quality of Service (QoS), for example Voice over Internet Protocol (VoIP), many restrictions due to the time delay may occur.
Recently, consideration has been given to the Fast Base Station Switching (FBSS) handover scheme because it is capable of performing a hard handover quickly. The FBSS handover scheme is a technology for performing handover in synchronization with a Mobile Station (MS) and a BS at a switching time from a serving BS to a target BS. Specifically, an MS that has previously been allocated signal and traffic resources for the candidate BSs to which it will move during handover, transmits information on the handover target BS to the serving BS over a Channel Quality Indicator Channel (CQICH) over which the MS periodically reports a status of Downlink (DL) radio resources. However, a need exists in the FBSS handover scheme for a detailed definition of operation parameters for the switching time between the serving BS and the target BS and for a scheme for scheduling traffic data in the serving BS via a relay station.